A Peculiar observation.more of a problem

Autor

Beitrag

abhi.pani
Inventar

#1 erstellt: 13. Okt 2006, 06:42

Hi Buddies,
This is something peculiar/unexpected that I noticed yesterday.
Actually I bought a new CRT TV along with a TV stand (a small one) yesterday. The TV Unit (TV placed on the TV stand) was finally placed in between the two BS speakers. Now when I sit at the sweet spot the TV is exactly in front of me. The distance between the center of the TV and the center of the speakers is around 4ft each side. The speaker's face and the TV screen is all on one straight line.

The peculiar thing I found is, now the sound image has lost depth. I dont get as holographic image I used to get before (i.e without anything in between the two speakers).
The sound is much more 2D now. The dissappearing act of the speaker has also reduced. I really dont know what is going on...is this a illusion or there is a audiophilic/acoustic reason for such a change in imaging characteristics ?

I just cant live with this kind of degradation for long.

I need help here..

P.S The speaker toe-in has not been changed.
The distance between the rear wall and the rear of the speaker is around 2ft.

[Beitrag von abhi.pani am 13. Okt 2006, 06:50 bearbeitet]

msb1
Stammgast

#2 erstellt: 13. Okt 2006, 07:01

A 'true' audiophile would never have a TV in the same room let alone between the speakers. It's like having a mirror there. The TV screen reflects sound waves smearing the image and causing lack of depth. This is the reason why many people have sound absorbing panels, tubes, etc. between/behind the speakers as well as on first reflection points on the side walls and the back wall.

Moving your speakers out towards you may help. And/Or throw a thick blanket on the TV when listening to music.

Here's a discussion on this topic:

http://db.audioasylu...levision&r=&session=

stevieboy
Stammgast

#3 erstellt: 13. Okt 2006, 07:43

cover your tv with a cloth cover and hear the difference. its what i do. if you could push the tv more towards the wall might help too.

Manek
Inventar

#4 erstellt: 13. Okt 2006, 07:48

loose the TV

abhi.pani
Inventar

#5 erstellt: 13. Okt 2006, 08:03

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Hi msb1,
That was a great thread and has infact revealed a lot about the problem that I thought was peculiar. Now it looks like something obvious. Today I will try out a few experiments and let you guys know the result.

cover your tv with a cloth cover and hear the difference. its what i do. if you could push the tv more towards the wall might help too.

Thanks for the suggestion buddy. That will be my first experiment..

abhi.pani
Inventar

#6 erstellt: 13. Okt 2006, 08:39

loose the TV

Kya Dushmani hai bhai...

Arj
Inventar

#7 erstellt: 13. Okt 2006, 09:01

well the above 2 suggestions are the best you can get for this

would you be able to try it out as an experiment ?

could you first push the TV back such that if you draw an imaginary line from the center of the woofer cone along the front face of the speaker, it should not extend to the screen of the tv ie the screen should be behind it.

try to gauge the soundstage now.

after this put a blanket/absorbing material on the tv (a thick quilt should sound good but look awful !)

now try again

the first case will ensure that there are no direct soundwaves reflected of the screen

the second will ensure that bending waves are always absorbed. apparently sound waves like light waves do "bend" around edges as well ansd also diffuse to some extent..these need to be absorbed.

if you can try it out and post the results am sure it will be very illuminating..

deaf
Stammgast

#8 erstellt: 13. Okt 2006, 10:12

Well the one guy who has succeded in this issue is Switch-it-on.He has a neat trick to make the tele disappear.Maybe you should ask for his input with regards to this.
Deaf.

abhi.pani
Inventar

#9 erstellt: 13. Okt 2006, 10:15

Sure Arj..I will be doing it today.
I cant push the TV backwards but can certainly pull the speakers forward. Even that upto a finite distance because I dont want to end up listening near-field.

As far as putting a quilt over the TV is concerned...it certainly looks like it can do the needful but can it be a "PERMANENT" solution ? How do I tell my wife that its going to stay on the TV forever...

The other solution might be to move the TV to another side of the room (if at all it has to stay in that room). But then the sofas has to be arranged in such a manner that one doesnt have to move it around while switching from Audio to TV..

Not easy..

Arj
Inventar

#10 erstellt: 13. Okt 2006, 10:46

dont worry about it too much with good placement you can get away to some extent without the blanket

eg my setup in paris is similiar

[Beitrag von Arj am 13. Okt 2006, 10:47 bearbeitet]

SWITCH-IT-ON
Ist häufiger hier

#11 erstellt: 13. Okt 2006, 11:26

deaf schrieb:

Well the one guy who has succeded in this issue is Switch-it-on.He has a neat trick to make the tele disappear.Maybe you should ask for his input with regards to this.
Deaf.

Dear abhi.pani and all at the forum.

Yes, Deaf is correct. I have been there.. done that.. moved on. I had (and still have) a Samsung 29 inch TV. Old model (10 Yrs). Huge guy. I tried nearly all the suggestions that are posted on this thread to varing results. Here are my experiences.

1) Thick Quilt - Only negates the reflection of the glass tube. The bloody box still sounds.

2) Placement - The TV (Plane of the Tube) has to be atleast 2 feet behind the front baffle of the speaker. If they are towed in, then 2 feet from where the line of the speakers meet in the centre. This works well. Quilt not required..

3) Placement - Moved the TV "off-centre". It was a foot before the left speaker's inner side wall, still two feet from the front baffle. Best results but.. The bloody box still sounds. Left channel got louder

4) The Breakthrough... finally - Two pairs of hands, a huge lift and it went twenty feet away from the sweet spot into the bedroom... The disappearing act..

Cheers.

deaf
Stammgast

#12 erstellt: 13. Okt 2006, 11:33

Dear Abhi Pani
I told you so, he is Houdini.
Deaf

Arj
Inventar

#13 erstellt: 13. Okt 2006, 11:38

SWITCH-IT-ON schrieb:

2) Placement - The TV (Plane of the Tube) has to be atleast 2 feet behind the front baffle of the speaker. If they are towed in, then 2 feet from where the line of the speakers meet in the centre. This works well. Quilt not required..

cool.. i got it done at around slightly less than 1 feet from the meeting point + quilt

of course the quilt is not present in the photo as wife was around then

i used 2 laser pointers placed on top of the speakers along their toe in to see where they intersect using a blank piece of paper !!

abhi.pani
Inventar

#14 erstellt: 13. Okt 2006, 13:16

4) The Breakthrough... finally - Two pairs of hands, a huge lift and it went twenty feet away from the sweet spot into the bedroom... The disappearing act..

Looks like thats more like my fate..

square_wave
Inventar

#15 erstellt: 13. Okt 2006, 13:26

I remember when I was checking out corrson’s valve preamplifier at home. I had moved the TV into my friend’s room and had the pre on the top equipment rack. It was soundstaging/imaging “nirvana “. Finally I had to move the TV back and move the pre down the rack. The imaging/soundstaging got smeared. The images started losing focus. Just for kicks we moved the TV out again Voila ! everything snapped back into place………
Best suggestion – Lose the bloody TV

I have moved the TV back on feet from the front panel of the speakers. It improved things a bit……...If the girlfriend / wife likes watchin movies in bed, you really can’t do much about it………us poor audiophiles are always at the receiving end………….isn’t it…………

zhopudey
Stammgast

#16 erstellt: 13. Okt 2006, 13:39

Get a LCD

square_wave
Inventar

#17 erstellt: 13. Okt 2006, 13:54

zhopudey schrieb:

Get a LCD :D

Good idea…………

SDhawan
Stammgast

#18 erstellt: 13. Okt 2006, 18:49

Hi !

Visuals are very highly distractive because vision takes precedence over hearing. When you see the source of sound you immediately associate it with that direction.

First try switching the TV off and shutting your eyes. Relax. Pause. Listen on to your favorite music for a couple of hours and then decide.

The resonance from boxes can alter the quantity of some frequencies of some sounds but would not change the quality of sound - in terms of phase difference between sounds from two channels and time delay of sound between two speakers. The extra sound from reflection or resonance from will always reach you later than the direct sound.

Just try.

Kamal
Stammgast

#19 erstellt: 13. Okt 2006, 20:45

The extra sound from reflection or resonance from will always reach you later than the direct sound.

Its this type of "extra" sound that smears the imaging.
Apart from the precaution of placing the Tv such that its well behind(1Ft shld be OK) the point where the imaginary line from the baffles of the speakers would meet,it wld be good to have a thin( 1" thick shld be enough)quilted cotton cover over the entire TV(the back plastic cover resonates pretty badly).
No need to throw the razai chupke se when the wife is out for her kitty party!

myriad
Ist häufiger hier

#20 erstellt: 14. Okt 2006, 17:14

I have made a tv cover with velvet cloth. Doesn't look all that bad :). The speakers are 5 feet from the rear wall.
Here's the pix.

http://img328.imageshack.us/img328/2906/1001672uc6.jpg

Manek
Inventar

#21 erstellt: 15. Okt 2006, 08:26

hey myriad ! love your choice of speakrs

so you have a stereo/surround setup ?

manek.

myriad
Ist häufiger hier

#22 erstellt: 15. Okt 2006, 08:50

Manek schrieb:

hey myriad ! love your choice of speakrs

so you have a stereo/surround setup ?

manek.

Yes Manek.

I think, if done properly, both stereo and HT can co exist at the same place :).
Me and my family love to watch movies on weekends and holidays and this is the only big room we have.
I have done some diy tweaks which have helped in getting the most of my system. I have placed all my equipment on inncer cycle tube platform. For me, they have worked better than roller balls, wooden cones or squash balls .
I installed a dedicated power line from the mains with Finolex 2.5 sqmm wires and changed all my stock power cords with diy braided pc made with Finolex 2.5sqmm wire. These are plain braided pc, not the shielded ones and they sound much cleaner and crispier than stock power cords.
In my opinion, the quality of power and the room is a major contributor in a good and bad sound.

Manek
Inventar

#23 erstellt: 15. Okt 2006, 09:09

you are right...I too did my separate mains wiring with finolex. I too use my own braided pc for my preamp and it really has worked well for me too. BTW which IEC connectors did you use ? The MX ones are pretty so so....

manek.

myriad
Ist häufiger hier

#24 erstellt: 15. Okt 2006, 11:06

Manek schrieb:

I didn't get any good, heavy duty IEC connectors. I am using the ones you get in local electronic market. It's a pain screwing up the wire in those connectors.

abhi.pani
Inventar

#25 erstellt: 15. Okt 2006, 19:12

SDhawan schrieb:

Hi Doc & others,
Thanks for all your input.
Doc, in this particular case there is no more illusions. At the first instance itself I found a drastic detorioration in imaging. I simply couldnt believe my ears. Couldnt even I find any logic behind all this. More importantly my TV was shut all throughout, hence visual distration was hardly present.

Finally after some discussion on the forum I tried some of the tricks. Putting a quilt immediately IMPROVED the imaging by around 50%. That was a great relief to me but on further investigation I found that the depth was lacking and the sound was still more 2D than 3D. Moving the speakers front to back had little scope since I lack length in the hall. Finally the TV is now in the other room and the MAGIC IS BACK.

But the problem couldnt be solved (entirely) with the TV back there is something I really worry.

stevieboy
Stammgast

#26 erstellt: 16. Okt 2006, 07:39

manek wot say we buy a pair of avitas/ amayas and split em? time sharing like rci holiday time sharing?

hehe

Manek
Inventar

#27 erstellt: 16. Okt 2006, 08:32

hee hee....interesting idea stevie....

BUT if I buy I never want to share my Avita's with Anyone